ROCK SPRINGS –– It started with pounding and cries for help coming from inside a school bus and quickly escalated into a major response involving multiple emergency response agencies.

The Southwest Wyoming Regional Airport hosted a multiagency disaster drill simulating a plane crash Saturday morning. The drill included the airport’s fire department, as well as both the Sweetwater County and Carbon County 911 dispatch centers, the Sweetwater County Sheriff’s Office, Castle Rock Ambulance Service and both Memorial Hospital of Sweetwater County and Aspen Mountain Medical Center, among others. More than 50 volunteers were also on hand to assist with the drill, many of whom were assigned roles as injured passengers or family and friends of the injured. The injured wore makeup to mimic the injuries ambulance crews would need to triage.

Prior to the start of the drill, Airport Manager Devon Brubaker encouraged volunteers to act as if they were in a plane, telling them to earn Oscars for their performances.

You guys are going to be in a plane crash,” Brubaker told volunteers.

Those involved in the drill actually called 911, with a goal of overwhelming the service and testing a feature that would kick emergency calls to the Carbon County dispatch center. Volunteers weren’t limited to injuries or those calling 911 — a couple of volunteers played the roles of people trying to trespass onto the airport runway to see what was happening. The trespassers were arrested and detained by sheriff’s deputies and Rock Springs Police Department Officers.

The live-action drill takes place every three years in accordance with Federal Aviation Administration and Transportation Security Administration regulations. The aim for the airport is to test the airport’s emergency plan when responding to emergency situations.